1. Cook the Pasta: In a large pot, boil salted water and cook the rotini or penne pasta according to package instructions. Drain and rinse under cold water to stop the cooking process.
2. Prepare the Corn: If using fresh corn, grill or roast it until charred. If using canned or frozen corn, simply measure out the amount needed.
3. Mix Vegetables: In a large mixing bowl, combine the cooked pasta, sweet corn, cherry tomatoes, red onion, and cilantro.
4. Prepare the Dressing: In a separate bowl, whisk together mayonnaise, sour cream, lime juice, chili powder, cumin, salt, and pepper until smooth.
5. Combine Everything: Pour the dressing over the pasta and vegetables, then gently toss until everything is well coated.
6. Add Cheese: Fold in the crumbled feta cheese for an added savory touch.
7. Chill (Optional): Cover the bowl with plastic wrap and refrigerate for about 30 minutes to let the flavors meld. This step is optional but enhances the taste.
8. Serve: Give the salad a final toss before serving to redistribute the dressing. Garnish with extra cilantro and lime wedges, if desired.

These simple steps will guide you through making this incredible Mexican Street Corn Pasta Salad with ease.